Twisted yarn package



Nov. 20, 1962 J. K. COCHRAN 3,064,922

TWISTED YARN PACKAGE Filed Aug. l0, 1960 INVENTOR. JO//A/ A. (DCI/@AN @www United States Patent Oilce 3,064,922 Patented Nov. 2i), 1962 3,064,922 TWISTED YARN PACKAGE John K. Cochran, Pine Township, Pa., assiguor to Pittsburgh Plate Glass Company, Pittsburgh, ita., a corporation of Pennsylvania Filed Aug. 10, 1%0, Ser. No. 48,634 1 Claim. (Cl. 242-175) The present invention relates to a twisted yarn package, and it has particular relation to a method of making such a package. The invention is applicable to the formation of packages of various types of yarn, but it has particular applicability to continuous lilament glass ber yarn packages.

it has been the practice to apply a twist to continuous lament glass liber strands by means of conventional ring twisting apparatus. A strand forming package is mounted on a driven spindle rotating at a constant speed. The strand is removed from the side of the package and passed downwardly through guides, tension devices and a ring traveler onto a twister tube mounted vertically on a rotating twister tube supporting spindle. The ring carrying Vthe traveler is mounted around the twister tube in a horizontal plane and is perpendicular to the axis of the tube. The ring reciprocates slowly in a vertical direction to build up the twisted yarn in a iilling wind with the succeeding turns in each layer being parallel to each other.

Glass ber strands are unique in their properties as compared to other natural or synthetic yarns. Glass liber strands contain about 2G() to 400` orl more tine individual glass iilaments. The individual filaments have a diameter of about 0.00623 to 0.00638 inch. The filaments do not stretch and they are easily broken by abrading against each other or by being abraded by rough surfaces across which they pass. Although the individual filaments have great tensile strength, there is a limit to the amount of tension which can be applied to the strands during processing without the individual filaments being abraded on the processing equipment and breaking. The strands usually do not break all at once but rather than one or several individual filaments are irst broken. When an individual filament is broken, fuzzing occurs due to buildup of the broken iilament at a guide, traveler, etc., and a fuzzy yarn is produced. A fuzzy yarn cannot be further fabricated with any degree of success because the fuzz soon clogs the fabricating equipment, for example, a loom, and causes a breakdown.

One problem which is troublesome in the twisting of glass liber yarn is the uneven build-up of turns of twisted This problem is particularly acute when the socalled milk bottle type of yarn package is formed. This type of package is formed on a twister tube with a wide flange on the bottom. The package is cylindrical in shape from the bottom up to near the top and the top portion is tapered inwardly. Such a package is designed for over end delivery of the twisted yarn for further fabrication.

In forming such a package, the ring is aligned with the twister tube so that its bottom limit of travel is just even with the intersection of the flange of the tube with the main portion of the tube. This theoretically produces a cylindrical bottom to the package which extends right down to the ange. As a practical matter, the ring usu ally hesitates at the bottom of its travel before starting up and this hesitation causes more yarn than desired to be built up at the bottom of the yarn package. Instead of forming a cylindrical package at the bottom of the tube, a hump is formed. It is diiiicult to remove the yarn from the hump without breaking the yarn or some of the individual larnents of the yarn. This can be compencording to the present invention.

sated for to some extent by adjusting the ring so that it does not travel all the way down to the ange, but instead stops slightly above the flange.

Again, as a practical matter, it is virtually impossible to have every ring and tube on a twisterl frame aligned exactly right. The thickness of the ilange on the bottom of the tube may vary rorn one tube to another. The mounting of the tube on the spindle may not be accurate. The ring may be incorrectly mounted with respect to the flange due to mistake in the accuracy of measurement or for other reasons.

lf the ring does not travel far enough on its downward stroke, an indented portion is formed at the bottom of the package. The outer turns of twisted strand at the bottom of the yarn package have no support and tend to fall from their place onto the top surface `of the ilange. When this occurs, the yarn at the bottom of the package becomes entangled and is difficult to unwind. Frequently, the yarn breaks during unwinding because oi this entanglement. It is then very diicult to find the end of the yarn to nish unwinding the rest of the package for it is trapped under other turns of yarn. The weavers are aware of these unwinding difculties and refuse to accept any twisted yarn where the yarn has fallen from place at the bottom of the package.

if the ring is -mounted with respect to the tube so that it travels below the level of the tl'ange, the yarn package on the tube is llared outwardly at the bottom. This ordi narily does not cause any unwinding problems if the yarn does not have any broken laments. Frequently, however, in such a package, the individual filaments are broken when they ride over the peripheral edge of the llange. This edge may have some nicks or other imperfections in it, and, as the strand passes over these nicks, some of the individual ilaments are broken. The fuzzy yarn thus produced is not satisfactory for the reasons discussed above.

lt is an object of this invention to produce on a flanged tube a package of twisted yarn having a cylindrical shape at the flanged end and which is free from the above defects caused by dwell of the ring at the bottom of its stroke and by misalignment of the ring and twister tube. It is a further object of this invention to produce a tightly wound yarn package which is free from sloughing oft of the yarn. It is desired to accomplish these objects without undue increases in the tension applied during the twisting of the yarn.

These and other objects of the invention are accomplished by adjusting the mounting of the ring with respect to the twister tube so that the plane of the ring is at a small angle, preferably about 3 to 7 degrees, from a plane which is perpendicular to the axis of the twister tube. With this arrangement the twisted yarn in each layer is tied together on the package by virtue of the fact that the succeeding turns of yarn cross each other at progressively changing, small angles.

A detailed description of the invention is provided in conjunction with a description of the drawing in which:

FIG. 1 is a diagrammatic elevation of a ring twisting apparatus suitable for use in the practice of the invention;

FIG. 2 is an elevation of a twister package illustrating a defect of the prior art;

FIG. 3 is a diagrammatic, partial isometric view of a twister package further illustrating a defect of the prior art, and

FIG. 4 is a view of a twister package produced ac- In FIG. 1 of the drawing there is shown diagrammatically a portion of a twisting frame constructed so as to permit the practice of the invention. In FIG. 1 the View is a side view of the apparatus as considered from the position of the operator, with the left side of the figure being the front side where the operator stands and the right side being the rear of the frame. A strand supply package is mounted above the twisting apparatus on a suitable rotatable support which is driven at a constant speed by suitable means (not shown). The strand is fed olf of the side of the strand supp-ly package 10 and passes through tension bars 12 and pigtail guide 14 on its way to the traveler 16 mounted in grooves 18 on ring 2d. rl`he ring 20 surrounds a vertically mounted spindle 24 which is mounted for rotation in suitable bearings 26 and rotated by means of belt 28 attached to the spindle and to suitable belt driving means (not shown). The ring, traveler, twister tube spindle and the means for driving the twister tube spindle are all conventional textile twisting equipment and are not considered part of this invention except insofar as the manner in which they are used. A tube 29 for receiving twisted yarn is shown mounted on the spindle 24 for rotation therewith. The tube may be keyed to the spindle or held thereon by friction for this purpose.

The ring 20 is mounted on a bar 30 which passes along the rear of the spindle 24 and its adjacent spindles on the twister frame. This bar is moved slowly up and down so as to traverse the ring vertically along the length of the twister tube 29 and distribute the yarn along the length of the tube. The means for moving the bar 30 may be conventional and is not shown. The mounting of the ring 2t) with respect to the bar 30 is different from conventional practice in that a Wedge 32 is inserted between the ring 20 and bar 30 so that the plane of the ring will be tilted slightly from a horizontal plane and not be exactly perpendicular to the axis of the spindle 24. The angle of the tilt is approximately 3 to 7 degrees, preferably about 6 degrees, and the importance of this angle will be further described in connection with the operation of the apparatus.

In FIG. 2 of the drawing there is shown an elevation of a tiwsted glass fiber yarn package 35 made according to the prior art. The yarn package is of the milk bottle shape and the bottom of the package is tapered outwardly to form a hump 40. The yarn on the package is wound in a filling wind with each turn parallel to each other. The hump 4t) is caused on the dwell of the ring at the bottom of its stroke.

In FIG. 3 there is shown another defect of the prior art where the bottom of the yarn package is indented or tapered inwardly at 41.

The parallel wind of the prior art permits the bottom turns of yarn to slough off at the periphery and fall down onto the fiange 42 of the tube as shown in a greatly enlarged View in FIG. 3. The turn of yarn 44 is shown lying on the top surface of the flange 42. As described above, when a package like this is formed and sent to a customer, it is returned because of the customerspast experiences with the ditiiculty in unwinding such a package.

These difiiculties are overcome by producing Vthe yarn package 46 shown in FIG. 4 by means of the modified twisting apparatus shown in FIG. l. From FIG. l it can be seen that one side of the ring 20 is higher than the other and consequently the traveler 16 as it travels around the grooves 18 in the ring -will be directing the twisted strand onto the rotating tube at different levels depending upon the position of the traveler on the ring. The traveler rotates rapidly on the ring in comparison to the vertical movement of the ring and thus the angle of succeeding turns of twisted yarn on the tube with respect to a perpendicular plane through the axis of the tube 29 varies from turn to turn. This angle may sometimes alternate to be a leading angle and then change to a trailing angle with respect to the perpendicular plane and vice versa. This causes the yarn to cross over itself occasionally on the tube and tie in the preceding layers and hold them in place on the tube. This prevents sloughing off of the i yarn as shown in FIG. 3. These angles which the yarn turns form with each other are small, i.e., up to about l5 degrees, and vary with each turn since the position of the traveler on the ring varies with each rotation of the spindle 24. The angular build of the yarn is illustrated in FIG. 4.

The tilting of the ring provides `better distribution of the yarn on the tube at the flanged end. When the ring and tube 25 are out of alignment with respect to vertical travel of the ring and an indentation is formed, or when a hump is formed because of the dwell of the ring at the bottom of its stroke, the tilting of the ring and the angular lay-down of the twisted strand on th-e tube at the bottom near the flange helps to distribute the yarn better at the indentation or hump and make the indentation or hump less severe, thereby minimizing the problem created by the indentation or hump. The indentation or hump is less severe than it would be if the ring were perpendicular to the twister tube axis.

The better distribution is accomplished in this way. When the ring is mounted in a plane that is perpendicular to the axis of the tube, the yarn is deposited on the package in the form of a spiral, exactly the same amount being deposited at every point on the tube if the moti-on of the ring is linear. If the ring is set at an angle other than degrees to the axis of the bobbin, it will then deposit through a certain distance at the end `of its stroke one half as much yarn as `during the rest of its travel. This distance is equal to the vertical distance between two horizontal, parallel planes passing through the opposed upper and lower edges of the tilted ring. By adjusting the angle of tilt of the ring from .a horizontal position, it is possible to reduce the amount of yarn deposited at the flange to compensate for the extra amount of yarn deposited because of the dwell `of the -ring at the bottom reversal point.

The angle of the tilt 4is `also important in the twisting operation for another reason. As stated above glass fiber strands :are unique in their properties and must be handled more -carefully than other types of 'synthetic yarn such as the synthetic polyamide or polyester fibers. The tension on the strand during the twisting must be carefully controlled. When the ring is tilted too much, the tension on the strand is too great while the traveler is moving uphill and is not sufiicient while the traveler is moving downhill in the `grooves on the ring. The traveler is seen to chatter and bump under such conditions. If there is too much tension, the individual filaments are likely to be broken and create fuzzy yarn. High tension in the yarn cuts a sharp-edged groove in the traveler and the groove breaks individual filaments as the yarn passes through the traveler. In addition the individual filaments tend to abrade each other when too much tension is applied.

If the -ring is not tilted enough the desired crossing of the strands is not obtained and the leveling out of the hump or indentation at the bottom of the package is not obtained. Also, the yarn package is not tight enough to prevent sloughing off of the yarn.

Although the present invention has been described with respect to specific details of certain embodiments thereof, it is not intended that such details serve as limitations upon the scope of the invention except insofar as set forth in the accompanying claim.

I claim:

A package of twisted continuous filament glass fiber yarn having a -conical portion .and a cylindrical portion which comprises a tube having a large ange on one end and twisted yarn built up around the tube in superposed layers extending along the length of the tube with the layers at the iianged end of the tube terminating at the flange .and being :a part of the cylindrical portion, each turn of yarn in each layer being at a small angle to the preceding turn, said angle alternating periodically and gradually throughout the length of each layer from a leading angle to a trailing angle and vice versa, certain turns in a layer ycrossing `over portions of eerta-in other turns in the sarne layer to hold the turns of twisted yarn rmly in place on the package.

References Cited in the le of this patent UNITED STATES PATENTS 2,345,245 Edfors Mar. 28, 1944 FOREIGN PATENTS Germany Apr. 6, 1904 Germany Apr. 6, 1906 Australia Dec. 10, 1958 Great Britain Nov. 23, 1927 Great Britain Aug. 27, 1958 

